Junk mail rejection system

ABSTRACT

To provide a junk mail rejection system which can effectively reject junk mail in electronic mail. When junk mail transmitted from many and unspecified persons is sent to a first electronic mail address registered in a first mail distribution service center, sources of the junk mail are not acceptable electronic mail addresses, and a reception enable unit rejects receiving the junk mail, thereby avoiding transmission of the junk mail to subscribers. On the other hand, the electronic mail transmitted from many and unspecified persons and not to be rejected by the reception enable unit is transmitted to a second electronic mail address. The electronic mail to the second electronic mail address received by a second mail distribution service center is forwarded to a third mail distribution service center, and a replacement unit replaces a source with an acceptable electronic mail address registered in the first mail distribution service center, and the electronic mail is transmitted to the first mail distribution service center. Since the source is set to an acceptable electronic mail address, the reception enable unit in the first mail distribution service center enables reception, and a subscriber can receive the electronic mail.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a junk mail rejection system forrejecting junk mail in electronic mail.

2. Description of the Related Art

Recently, as various networks such as Internet, etc. have been developedand wireless terminal equipment has made remarkable progress, more andmore information has been transmitted and received by electronic mail,and a number of users utilize electronic mail personally and forbusiness.

On the other hand, with an increasing utilization factor of electronicmail, there arises the social problem that the amount of electronic mailfrom an undesired source, that is, junk mail, has largely increased.Now, an Internet service system using a wireless telephone as an exampleis explained. There is a center capable of gaining access through anetwork such as Internet, etc., and an electronic mail address isassigned to a wireless telephone of a subscriber. When electronic mailis transmitted to the electronic mail address of a subscriber, theinformation about the electronic mail is transmitted from the center tothe wireless telephone of the subscriber if the electronic mail istransmitted through the center and the wireless telephone of thecorresponding subscriber is set ON. If the electronic mail address ofthe subscriber is correctly specified as a destination, then electronicmail is received by the wireless telephone regardless of the intentionof the subscriber to receive the mail, thereby generating junk mail.Especially when the service fee is charged to a receiving subscriberdepending on the amount of information received by the subscriber fromthe center in the system of the Internet service, the total amount ofpayment of the subscriber who receives junk mail increases due to thejunk mail, thereby causing the subscriber to suffer a loss. One of thesolving methods is to change the system into a system in which a fee ischarged to a transmitter's account, or into a system in which for eachpiece of electronic mail, a subscriber can select whether or not theelectronic mail is to be received. However, it means to largely changean entire system, and requires a high cost. Other than changing thesystem, there is a method of avoiding a charge to a receiver when theamount of information is equal to or smaller than a predeterminedamount. However, this method cannot completely avoid a loss by junk mailhaving a large amount of information. Furthermore, there can also be amethod of changing the electronic mail address of a subscriber, butchanging an electronic mail address requires notifying all possibletransmitters of desired electronic mail of the change of the electronicmail address, thereby imposing a heavy load on the subscriber.Otherwise, there can be an existing system in which a center includesmeans for performing capabilities of: ‘specified reception’ forreceiving only mail whose source is specified source electronic mailaddress; ‘specified rejection’ for rejecting only mail whose source isspecified source electronic mail address; ‘batch rejection’ forrejecting reception of all electronic mail, etc. However, the ‘specifiedreception’ is restricted in the number of electronic mail addresses tobe specified, and electronic mail to be received cannot be received ifit is not specified. Similarly, since reception of all electronic mailis rejected in the ‘batch rejection’, electronic mail to be receivedcannot be received. Additionally, since a source electronic mail addressof junk mail can be constantly changed, the junk mail cannot beeffectively avoided in the ‘specified rejection’.

Another problem with the junk mail is that old necessary electronic mailis removed by a large amount of junk mail received when there is arestriction in the number of pieces of electronic mail to be stored foreach subscriber and the predetermined number of pieces of laterelectronic mail is stored.

Furthermore, malicious electronic mail can be acts of terrorism ofdamaging the function of mail at the destination by intentionallyconcentrating a large amount of junk mail. The acts of terrorism notonly aims at a person but also aims at an organization such as a largecompany, government and municipal offices, etc. whose domain names areoften published, and the user name in the electronic mail address ofeach member can be simply the name of the member and the pattern of theaddress is simple. Therefore, a terrorist can easily transmit electronicmail to the electronic mail address of a member of an organization.Furthermore, if each member suffers the acts of terrorism when theelectronic mail received by a server of the organization is set to betransferred to his or her own wireless telephone, then old but necessaryelectronic mail are all cleared as described above. Additionally, itrequires a cost of using a telephone line to delete a large amount ofunnecessary mail, thereby badly damaging the subscriber.

Whereas junk mail causes the above mentioned damage, some electronicmail belonging to normal junk mail to be transmitted at random to anumber of general subscribers does not function as junk mail dependingon the type of receiving subscriber. That is, although electronic mailfunctions as junk mail for some subscribers, it is not junk mail if thecontents of the mail are desired by other subscribers. Namely, such mailhas a possibility of creating an mail distribution industry moreeffective than conventional direct mail distributed by conventionalmail.

SUMMARY OF THE INVENTION

In view of the foregoing and other drawbacks, disadvantages and problemsof the conventional methods and structures, the first object of thepresent invention is to provide a junk mail rejection system capable ofeffectively preventing junk mail.

The second object of the present invention is to provide a junk mailrejection system capable of preventing the damage by junk mailtransmitted with a view to acts of terrorism.

The third object of the present invention is to provide a junk mailrejection system in which electronic mail from any source nottransmitting junk mail depending on the subscriber is reception enabled.

To attain the above mentioned object, the junk mail rejection systemaccording to the present invention includes:

a first mail distribution service center having a database in which afirst electronic mail address of a subscriber is registered, receivingelectronic mail transmitted to the first electronic mail address througha cable/wireless network, and transmitting the electronic mail to aterminal of the subscriber;

a second mail distribution service center having a database in which asecond electronic mail address of the subscriber is registered, andreceiving electronic mail to the second electronic mail address througha cable/wireless network; and

a third mail distribution service center having a database in which athird electronic mail address of the subscriber is registered, andreceiving electronic mail to the third electronic mail address through acable/wireless network, wherein

the first mail distribution service center registers in the database oneor more source electronic mail addresses as acceptable electronic mailaddresses, associated with the first electronic mail address, from whichelectronic mail can be transmitted to the terminal of a subscriber amongsource electronic mail addresses of electronic mail addressed to thefirst electronic mail address, and includes: reception means forreceiving electronic mail to the first electronic mail address;reception enable means for determining whether or not a sourceelectronic mail address of electronic mail received by the receptionmeans is an acceptable electronic mail address registered in thedatabase; and distribution means for transmitting the electronic mail toa terminal of a subscriber only the case when the reception enable meansdetermines that it is an acceptable electronic mail address;

the second mail distribution service center registers an electronic mailaddress of a transfer destination of a subscriber with the databaseassociated with a second electronic mail address, and includes receptionmeans for receiving electronic mail to the second electronic mailaddress; and transfer means for forwarding the electronic mail receivedby the reception means to a third mail distribution service centerdirectly through a cable/wireless network, or through another center;and

the third mail distribution service center registers an electronic mailaddress of a transfer destination of a subscriber with the databaseassociated with a third electronic mail address, and comprises receptionmeans for receiving electronic mail to the third electronic mailaddress; replacement means for replacing a source electronic mailaddress of the electronic mail received by said reception means with oneof the acceptable electronic mail addresses; and transfer means forforwarding the electronic mail whose source electronic mail address hasbeen replaced by said replacement means to said first mail distributionservice center directly through a cable/wireless network, or throughanother center.

To attain the above mentioned object, an intermediate mail distributionservice center according to the present invention is provided between

a first mail distribution service center having a database in which afirst electronic mail address of a subscriber is registered, receivingelectronic mail transmitted to the first electronic mail address througha cable/wireless network, and transmitting the electronic mail to aterminal of the subscriber only when a source of the electronic mail hasan acceptable electronic mail address permitted in advance fortransmission to a terminal of the subscriber and

a second mail distribution service center having a database in which asecond electronic mail address of the subscriber is registered, andreceiving electronic mail to the second electronic mail address througha cable/wireless network, and includes:

reception means for receiving electronic mail to a second electronicmail address received by the second mail distribution service center;

replacement means for replacing a source of the electronic mail receivedby said reception means with the acceptable electronic mail addressdetermined by the first mail distribution service center; and

transfer means for allowing the electronic mail replaced by thereplacement means to be transmitted to the first mail distributionservice center.

The second electronic mail address can be registered as one of theacceptable electronic mail addresses registered in the database of thefirst mail distribution service center, and the replacement means of thethird mail distribution service center replaces a source electronic mailaddress with the second electronic mail address.

The replacement means can replace destination data of the electronicmail received by the reception means with the source data, and replacethe source data with the destination data.

The replacement means can add the source data and/or destination databefore replacement to the information of a body of electronic mail.

The third mail distribution service center can further include mailreception amount restriction means for determining whether or not theelectronic mail received in a predetermined time period has exceeded apredetermined amount, and the electronic mail is rejected when theelectronic mail has exceeded the predetermined amount.

The third mail distribution service center can have a database storingfor each subscriber an identification code indicating an attribute of asubscriber and an attribute of a transmitter whose electronic mail ispermitted by the subscriber, and direct electronic mail transmissionmeans for transmitting electronic mail to a specified mail address of asubscriber selected by the identification code.

The direct electronic mail transmission means can transmit electronicmail selected at random or intentionally as premier mail.

The third mail distribution service center can have a receiver rankdatabase storing the number of pieces of obtained premier mail for eachsubscriber, and allows the contents of the receiver rank database to beviewed on WEB as is or after being processed.

The third mail distribution service center can have a transmitter rankdatabase storing the number of votes of subscribers who evaluate atransmitter for each transmitter of electronic mail transmitted by thedirect electronic mail transmission means, and allows the contents ofthe transmitter rank database to be viewed on WEB as is or after beingprocessed.

When junk mail transmitted from many and unspecified persons is sent toa first electronic mail address registered in the first maildistribution service center, since the sources of the junk mail are notacceptable electronic mail addresses, the reception enable means rejectsreceiving the junk mail, thereby avoiding transmission of the junk mailto subscribers. On the other hand, the electronic mail transmitted frommany and unspecified persons and not to be rejected by the receptionenable means is transmitted to a second electronic mail address. Theelectronic mail to the second electronic mail address received by thesecond mail distribution service center is transferred to the third maildistribution service center (intermediate mail distribution servicecenter), and the replacement means replaces the source with theacceptable electronic mail address registered in the first maildistribution service center, and the electronic mail is transmitted tothe first mail distribution service center. Since the replaced source isset to an acceptable electronic mail address, the reception enable meansin the first mail distribution service center enables reception, and asubscriber can receive the electronic mail.

Thus, the subscriber certainly receives the electronic mail whose sourceelectronic mail address is not registered as acceptable electronic mailaddress, but which should be received by the subscriber when theelectronic mail is transmitted from the source electronic mail address,thereby removing only junk mail. When the second mail distributionservice center is a target of junk mail, the subscriber receives thejunk mail through the first mail distribution service center. In thiscase, the risk of receiving junk mail can be shared between the firstmail distribution service center and the second mail distributionservice center, and the problem that only the first mail distributionservice center receives the damage of receiving the junk mail can beavoided. Furthermore, when the first electronic mail address is changed,it is not necessary to notify all related subscribers of the changedelectronic mail address, but it is necessary only to notify the thirdmail distribution service center (intermediate mail distribution servicecenter) of the change.

Additionally, the electronic mail to the second electronic mail addressof the second mail distribution service center includes the informationabout the second electronic mail address as a destination. Therefore, ifthe replacement means of the third mail distribution service center setsthe source as the second electronic mail address, then the electronicmail to the second electronic mail address of the second maildistribution service center can be received through the first maildistribution service center by setting the second electronic mailaddress as an acceptable electronic mail address.

Furthermore, by setting the source data as the destination data, theoriginal source data contained in the original electronic mail can bereserved, thereby allowing the receiving subscriber to know who is thetransmitter.

In addition, by adding the destination data and the source data beforereplacement to the information of the body of electronic mail, thesubscriber can certainly grasp them from the body of the electronicmail.

Also by means of mail reception amount restriction means, acts ofterrorism can be avoided.

Furthermore, subscribers can register in advance identification codesindicating the attributes of sources, the electronic mail from which canbe allowable for the subscribers to be received. In the case, theelectronic mail from the source belonging to the identification codesthat the subscribers registered in advance is transmitted to thesubscribers by the direct electronic mail transmission means. Thus,corresponding traders belonging to the registered identification codecan transmit direct electronic mail to the subscriber who registered theidentification code, thereby utilizing the mail as effective marketingmeans. Furthermore, since an identification code also indicates theattribute of a subscriber, a transmitter who transmits direct electronicmail can effectively transmit electronic mail.

Including premier mail in the direct electronic mail urges a subscriberto receive the largest possible amount of direct electronic mail,thereby successfully transmitting more direct electronic mail to alarger number of subscribers.

Additionally, ranking subscribers based on the amount of obtainingpremier mail and publishing the ranking result urges the subscribers toreceive a larger amount of direct electronic mail with a view toobtaining premier mail. As a result, the third mail distribution servicecenter (intermediate mail distribution service center) is used morefrequently.

By a receiver voting for a transmitter who asks the third maildistribution service center to transmit direct mail, the transmitter isurged to endeavor to be liked by the receiver, and obtain a largernumber of votes. Thus, a more effective advertisement is planned, andthe third mail distribution service center (intermediate maildistribution service center) is used more frequently.

The present disclosure relates to subject matter contained in JapanesePatent Application Nos. 2001-310115, filed on Oct. 5, 2001, which areexpressly incorporated herein by reference in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other purposes, aspects and advantages will be betterunderstood from the following detailed description of preferredembodiments of the invention with reference to the drawings, in which:

FIG. 1 shows an entire configuration of a first embodiment of a junkmail rejection system according to the present invention;

FIG. 2 is a block diagram of the entire junk mail rejection systemaccording to the present invention;

FIG. 3 shows a relationship between the first to third mail distributionservices and the first to third electronic mail addresses;

FIG. 4 shows a transfer relationship between the first to third maildistribution services and the first to third electronic mail addresses;

FIG. 5 is a part of a view showing a principle of rejecting junk mail;

FIG. 6 is a remaining part of FIG. 5 showing the principle of rejectingjunk mail;

FIG. 7 shows a part of a source display of electronic mail before andafter the process performed by the replacement means;

FIG. 8 is an entire block diagram of a second embodiment of the junkmail rejection system according to the present invention;

FIG. 9 shows an example of a setting screen of restricting the amount ofreceived mail;

FIG. 10 shows possible patterns of acts of terrorism;

FIG. 11 is an entire block diagram of a third embodiment of the junkmail rejection system according to the present invention;

FIG. 12 shows an example of inquiry items for determination ofidentification codes, and selection items;

FIG. 13 shows an example of a list of identification codes stored in theidentification code listing database;

FIG. 14 shows an example of displaying a list of publishedidentification codes;

FIG. 15 is an entire block diagram according to a fourth embodiment ofthe junk mail rejection system according to the present invention; and

FIG. 16 shows examples of receivers of higher ranks.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments of the present invention are explained below byreferring to the attached drawings.

(Rejecting Junk Mail)

FIG. 1 shows an entire configuration of a junk mail rejection systemaccording to the present invention.

Reference numeral 10 denotes a first mail distribution service centerfor providing a first mail distribution service. In this embodiment, thefirst mail distribution service is an Internet service of a wirelesstelephone. As described later, the center 10 comprises distributionmeans for distributing information of an electronic mail to a wirelesstelephone 40 of a subscriber of the Internet electronic mail service(that is, the first mail distribution service) through a cable/wirelessnetwork. According to the embodiment, a center for offering an Internetelectronic mail service of a wireless telephone is used as the firstmail distribution service center 10. However, the present invention isnot limited to this application, but a commercial Internet provider, oran Internet provider managed by a company, a university, an institute,etc. can be used as the first mail distribution service center 10. Inthis case, the information of the electronic mail can be transmittedfrom the Internet provider to a computer, a mobile information terminal,a cable telephone unit, etc. operated by a subscriber through Internet.The important object in this system is to reject the junk mail when asubscriber receives the electronic mail transmitted from the first maildistribution service center 10 using a wireless telephone, a mobileinformation terminal, a cable telephone unit, a computer, etc.

Reference numeral 20 denoted a second mail distribution service centerfor providing a second mail distribution service. The second maildistribution service center 20 can be, for example, a commercialInternet provider, or an Internet provider managed by a company, auniversity, an institute, etc., and a subscriber of the first maildistribution service has to also subscribe to the second maildistribution service. The second mail distribution service center 20 hastransfer means for forwarding, as described later, the electronic mailaddressed to a subscriber and transmitted to the second maildistribution service center 20 to a third mail distribution servicecenter 30 explained below.

Reference numeral 30 denotes a third mail distribution service center.The third mail distribution service center 30 mainly performs a processfor rejecting the junk mail. Subscribers of the first mail distributionservice and the second mail distribution service also have to besubscribers of the third mail distribution service.

FIG. 2 is a block diagram of the entire junk mail rejection system. Thefirst mail distribution service center 10 has a WWW server 100 which canbe connected to the Internet. The WWW server 100 comprises a CPU, RAM,ROM, a communications interface circuit, a storage device such as afixed disk, etc. not shown in FIG. 2. The storage device is furtherprovided with: a subscriber database 120 for storing the firstelectronic mail address of a subscriber, a wireless telephone number,and other attribute information about the subscriber; a mailbox 122 forstoring the information of electronic mail transmitted to a firstelectronic mail address for each first electronic mail address of thesubscriber; and a reception specified database 124 for storing theinformation about the electronic mail address (acceptable electronicmail address) of the source of the electronic mail permitted by thesubscriber for reception for each first electronic mail address of thesubscriber. The program stored in the WWW server 100 is executed by theCPU to allow the WWW server 100 to perform the following functions. Toperform the functions, the WWW server 100 comprises: reception means 110for receiving the electronic mail specifying the IP address of the WWWserver 100 and storing it in the mailbox 122; distribution means 112 fortransmitting the electronic mail received by the WWW server 100 to thewireless telephone 40 at the destination; and reception enable means 116for determining whether or not the electronic mail address of the sourceof the electronic mail received by the reception means 110 is theacceptable electronic mail address registered in the reception specifieddatabase 124.

Like the first mail distribution service center 10, the second maildistribution service center 20 has a WWW server 200 which can beconnected to the Internet. The WWW server 200 comprises a CPU, a RAM, aROM, a communications interface circuit, a storage device such as afixed disk, etc. not shown in FIG. 2. The storage device is furtherprovided with: a subscriber database 220 for storing the secondelectronic mail address of a subscriber and other attribute informationabout the subscriber; a mailbox 222 for storing the information ofelectronic mail transmitted to a second electronic mail address for eachsecond electronic mail address of the subscriber; and a transfer addressdatabase 224 for storing the information about the forwarding electronicmail address to which the electronic mail transmitted to the secondelectronic mail address is to be forwarded, for each second electronicmail address of the subscriber. The program stored in the WWW server 200is executed by the CPU to allow the WWW server 200 to perform thefollowing functions. To perform the functions, the WWW server 200comprises: reception means 210 for receiving the electronic mailspecifying the IP address of the WWW server 200 and storing it in themailbox 222; and transfer means 212 for forwarding the electronic mailreceived by the WWW server 200 to the forwarding electronic mail addressstored in the transfer address database 224.

Like the first mail distribution service center 10 or the second maildistribution service center 20, the third mail distribution servicecenter 30 has a WWW server 300 which can be connected to Internet. TheWWW server 300 comprises a CPU, a RAM, a ROM, a communications interfacecircuit, a storage device such as a fixed disk, etc. not shown in FIG.2. The storage device is further provided with: a subscriber database320 for storing the third electronic mail address of a subscriber andthe attribute information about other subscribers; a mailbox 322 forstoring the information of electronic mail transmitted to a thirdelectronic mail address for each third electronic mail address of thesubscriber; and a transfer address database 324 for storing theinformation about the forwarding electronic mail address to which theelectronic mail transmitted to the third electronic mail address of asubscriber is to be forwarded, for every third electronic mail addressof the subscriber. The program stored in the WWW server 300 is executedby the CPU to allow the WWW server 300 to perform the followingfunctions. To perform the functions, the WWW server 300 comprises:reception means 310 for receiving the electronic mail specifying the IPaddress of the WWW server 300 and storing it in the mailbox 322;transfer means 312 for forwarding the electronic mail received by theWWW server 300 to the forwarding electronic mail address stored in thetransfer address database 324; and replacement means 314 for replacingthe source of the electronic mail received by the reception means 310with the destination.

Described below will be the operation of rejecting junk mail in thesystem with the above mentioned configuration.

As described above, the subscriber subscribes to all of the Internetelectronic mail service (first mail distribution service) of the firstmail distribution service center 10, the second mail distributionservice of the second mail distribution service center 20, and the thirdmail distribution service of the third mail distribution service center30. The subscriber obtains the first, second, and third electronic mailaddresses respectively in the mail distribution service centers 10, 20and 30. The subscriber (TARO) in this example is assumed to subscribeto, for example, three types of the second mail distribution services,that is, two commercial Internet provider and an Internet provider for acompany to which the subscriber belongs. As a practical example, thefirst electronic mail address is taro@keitai.ne.jp, the three types ofthe second electronic mail addresses are taro@nif.ne.jp, taro big.ne.jp,and taro@kigyo.co.jp, and the third electronic mail address istaro@dasp.com as shown in FIG. 3.

In the first mail distribution service, the second electronic mailaddresses taro@nif.ne.jp, taro@big.ne.jp, and taro@kigyo.co.jp areregistered in the reception specified database 124 corresponding to thefirst electronic mail address taro@keitai.ne.jp of the subscriber asacceptable electronic mail addresses. In addition to these addresses,any other mail addresses requested to be received by the subscriber, forexample, the electronic mail address tomo1@keitai.ne.jp of a friend 1,the electronic mail address tomo2@kigyo2.ne.jp of a friend 2, etc. canbe registered as acceptable electronic mail addresses. In the threetypes of second mail distribution services, the third electronic mailaddress taro@dasp.com is registered in each transfer address database224 as a forwarding electronic mail address corresponding to the secondelectronic mail addresses taro@nif.ne.jp, taro@big.ne.jp, andtaro@kigyo.co.jp of the subscriber, respectively. In the third maildistribution service, the first electronic mail addresstaro@keitai.ne.jp is registered in the transfer address database 324 asa forwarding electronic mail address corresponding to the thirdelectronic mail address taro@dasp.com of the subscriber (refer to FIG.4).

As shown in FIGS. 5 and 6, assume that electronic mail is transmitted tothe subscriber from the friend 1. The electronic mail address of thesource of the electronic mail is the electronic mail address of thefriend 1, that is, from=tomo1@keitai.ne.jp, and the electronic mailaddress of the destination is the first electronic mail address, thatis, to=taro@keitai.ne.jp. The information of the electronic mailtransmitted to the first mail distribution service center 10 through acable/wireless network is received by the reception means 120 of thefirst mail distribution service center 10, and then the reception enablemeans 116 determines whether or not the source address of the electronicmail is an acceptable electronic mail address. In this case, it is oneof the acceptable electronic mail addresses, determined to beacceptable, and stored in the mailbox 122 corresponding totaro@keitai.ne.jp. Then, the information of the electronic mail istransmitted by the distribution means 112 to the wireless telephone 40of the subscriber, and the subscriber can correctly receive theelectronic mail of the friend 1 whose mail is reception enabled.Similarly, the electronic mail of the friend 2 can be received.

When junk mail is transmitted by using the first electronic mail addressof the subscriber as a target, the electronic mail address of the sourceis the electronic mail address of the junk mail transmitter, that is,from=meiwaku@meiwaku.co.jp, and the destination electronic mail addressis the first electronic mail address, that is, to=taro@keitai.ne.jp. Itis received by the reception means 110 of the first mail distributionservice center 10, and then, the reception enable means 116 determineswhether or not the source address of the electronic mail is anacceptable electronic mail address. Since junk mail has not anacceptable electronic mail address and is rejected, and is not stored inthe mailbox 122. The distribution means 112 returns rejectionnotification mail to the source, thereby rejecting the junk mail to thesubscriber and successfully avoiding damage.

However, only the mail from the electronic mail addresses registered inthe reception specified database 124 can be received in the abovementioned method. In addition to the friends 1 and 2, friends 3, 4, . .. who possibly transmit electronic mail to the subscriber, and whoseelectronic mails are requested to be received by the subscriber arenotified of any of the second electronic mail addresses taro@nif.ne.jp,taro@big.ne.jp, and taro@kigyo.co.jp for transmission of electronicmail. Assume that the friend 3 transmits electronic mail usingtaro@nif.ne.jp as a destination. The information about the electronicmail transmitted to the second mail distribution service center 20through the Internet is received by the reception means 210 of thesecond mail distribution service center 20, and is stored in the mailbox222. Simultaneously, the information of the electronic mail is forwardedby the transfer means 212 to the third electronic mail addresstaro@dasp.com of the third mail distribution service center 30. At thistime, the information of the source and destination maintains to be theoriginal. The source is the electronic mail address of the friend 3,that is, from=tomo3@kigyo3.co.jp, and the destination is the secondelectronic mail address, that is, to=taro@nif.ne.jp. However, the pathinformation about the electronic mail is the third electronic mailaddress, that is, for=taro@dasp.com as forwarding address. Theelectronic mail is received by the reception means 310 of the third maildistribution service center 30, and is stored in the mailbox 322. Then,the replacement means 314 replaces the source with the destination, andthe destination with the source. That is, the source is set tofrom=taro@nifne.jp, and the destination is set to to=tomo3@kigyo3.co.jp.As shown in FIG. 7, the sentence of ‘This mail has been transmitted fromtomo3@kigyo3.co.jp to taro@nif.ne.jp.’ is inserted into the body data ofthe electronic mail. The tomo3@kigyo3.co.jp has been converted into hottext, and if it is clicked, it activates a mailer for reply mail.

The transfer means 312 forwards the information of the electronic mailto the first electronic mail address taro@keitai.ne.jp of the first maildistribution service center 10. The reception means 120 of the firstmail distribution service center 10 receives the information, and thereception enable means 116 determines whether or not the source addressof the electronic mail is an acceptable electronic mail address. At thistime, the source of the electronic mail is taro@nif.ne.jp which is anacceptable electronic mail address. Therefore, the mail can be received,and the distribution means 112 transmits the information of theelectronic mail to the wireless telephone 40 of the subscriber.Therefore, the subscriber does not have to specify its receptionpermission in advance, but the electronic mail of the friend 3 whosemail is to be reception-enabled can be correctly received when it istransmitted.

Thus, the junk mail addressed to the first electronic mail addresstaro@keitai.ne.jp of the subscriber registered in the first maildistribution service center 10 can be rejected, and the electronic mailfrom a person whose mail is to be reception-enabled, other than thereception-specified mail, can be received. When junk mail is addressedto the second electronic mail addresses taro@nif.ne.jp, taro@big.ne.jp,and taro@kigyo.co.jp, the replacement means 314 of the third maildistribution service center 30 automatically forwards the junk mail tothe wireless telephone 40 through the first mail distribution servicecenter 10. However, in this case, the risk of the first maildistribution service center 10 is the same in level as the risk of theInternet provider managed by other commercial providers, companies,universities, institutes, etc. That is, only when junk mail is addressedto the second mail distribution service center 20, the first maildistribution service center 10 is a target of the junk mail, therebyavoiding the concentration of damage on the first mail distributionservice center 10 only. Therefore, the risk of receiving junk mail canbe shared among all first and second mail distribution service centers10 and 20.

Described below will be the case in which junk mail is addressed to thethird mail distribution service center 30. When the reception means 310of the third mail distribution service center 30 receives junk mail, thereplacement means 314 replaces the source with the destination, and thedestination with the source. That is, the source is the third electronicmail address taro@dasp.com, and the destination is the electronic mailaddress of the junk mail transmitter, that is, meiwaku@meiwaku.co.jp.The mail is forwarded to the first mail distribution service center 10.Since the third electronic mail address taro@dasp.com is not registeredas an acceptable electronic mail address in the reception specifieddatabase 124 of the first mail distribution service center 10, thereception enable means 116 rejects receiving the junk mail. Thus, thereception of the junk mail can be rejected.

In the above mentioned embodiment, a second replacement means forreplacing the source with the destination can be provided in order torestore the source and the destination replaced by the replacement means314 to the original states before distributing electronic mail from thedistribution means 112 of the first mail distribution service center 10to the wireless telephone 40.

(Protection Against Acts of Terrorism)

As described above, according to the first embodiment, the risk ofreceiving junk mail can be shared among all first and second maildistribution service centers. Described below will be the system forprotection against damage from concentrative and intentionaltransmission of a large amount of junk mail.

FIG. 8 is a block diagram of a configuration of a second embodiment ofprotection against terrorism. The configuration which is the same as orsimilar to that shown in FIG. 1 is assigned the same reference numeral,and the detailed explanation is omitted here. The second embodiment isdifferent from the first embodiment in that it comprises a mailreception amount restriction means 316 and a setting means 318 asfunctions that the WWW server 300 performs by the program stored in theWWW server 300 of the third mail distribution service center 30. The WWWserver 300 is provided with a reception amount restriction setting valuedatabase 326, and the reception amount restriction setting valuedatabase 326 stores the set values of the mail reception monitor timeand the number of restrictions for each of the third electronic mailaddress of the subscriber. The set values can be set on the WEB by asubscriber. After the setting means 318 is activated, the setting means318 receives the set values input from the wireless telephone 40 of thesubscriber or the computer, and stores it in the reception amountrestriction setting value database 326. FIG. 9 shows an example of a setscreen of a display of the terminal. The mail reception monitor time andthe number of restrictions can be freely selected by a subscriber.However, the set items are not limited to this application. For example,one of them can be a predetermined value.

In the present embodiment, the mail reception amount restriction means316 is constantly activated, and determines whether or not the amount ofelectronic mail has reached the set value (M pieces) in the set period(N minutes) based on the reception time of electronic mail received bythe reception means 310 of the third mail distribution service center 30and the set values stored by the reception amount restriction settingvalue database 326. If the amount is equal to or smaller than thepredetermined value, then the electronic mail is forwarded by thetransfer means 312 to the first mail distribution service center 10after the replacing process is performed by the replacement means 314 asin the first embodiment. If the amount has exceeded the predeterminedvalue, then the transfer of the overflowing mail to the first maildistribution service center 10 is stopped. The electronic mail exceedingthe predetermined value is deleted by the mail reception amountrestriction means 316. Although there is a large amount of received mailall of which is not junk mail, and there are non-junk mail and junk mailin a mixed manner, non junk mail is deleted when it exceeds apredetermined value. However, non-junk mail must have been forwarded tothe third mail distribution service center 30 from all second maildistribution service centers 20, and these pieces of electronic mail arestored in the mailbox 222 of the second mail distribution service center20. Therefore, the subscriber can read the deleted mail by accessing thesecond mail distribution service center 20 and viewing the receivedmail.

FIG. 10 shows possible patterns of acts of terrorism. In FIG. 10,terrorism 1 indicates the case in which a large amount of electronicmail has been transmitted to any of the second electronic mail addressestaro@nif.ne.jp, taro@big.ne.jp, and taro@kigyo.co.jp.

Terrorism 2 indicates the case in which a large amount of electronicmail has been transmitted to the third electronic mail address of thethird mail distribution service center 30 by pretending that mail hasbeen forwarded from any of the second electronic mail addressestaro@nif.ne.jp, taro@big.ne.jp, and taro@kigyo.co.jp of the second maildistribution service center 20 (that is, any of the second electronicmail addresses is designated as the destination).

Terrorism 3 indicates the case in which pretending as if electronic mailhas been forwarded from the third electronic mail address of the thirdmail distribution service center 30, a large amount of mail has beentransmitted to the first electronic mail address of the first maildistribution service center 10 with the destination is designated to beany of the second electronic mail addresses taro@nif.ne.jp,taro@big.ne.jp, and taro@kigyo.co.jp.

Terrorism 4 indicates the case in which a large amount of electronicmail has been transmitted to the third electronic mail address of thethird mail distribution service center 30 from inside the second maildistribution service center 20.

Terrorism 5 indicates the case in which a large amount of electronicmail has been transmitted to the first electronic mail address of thefirst mail distribution service center 10 by pretending as if the mailhas been transmitted from an acceptable electronic mail address.

Terrorism 6 indicates that a large amount of electronic mail has beentransmitted to the third electronic mail address of the third maildistribution service center 30 by pretending as if the mail has beentransmitted to an acceptable electronic mail address.

In the above mentioned terrorism 1 to 6, although processes areperformed by the replacement means 314 of the third mail distributionservice center 30, the junk mail passes through the reception enablemeans 116 of the first mail distribution service center 10. Therefore,with the configuration according to the first embodiment, a subscribersuffers acts of terrorism of a large amount of mail. However, the mailreception amount restriction means 316 of the third mail distributionservice center 30 can avoid the terrorism 1, 2, 4, and 6.

The terrorism 3 and 5 cannot be rejected by the mail reception amountrestriction means 316, but can be avoided by providing similar mailreception amount restriction means in the first mail distributionservice center 10.

(Reception from Unspecified Source)

Described below will be the system of not equally and completelyrejecting junk mail, but permitting the reception of electronic mailfrom an unspecified source which is not junk mail depending on thesubscriber.

FIG. 11 is a block diagram of the configuration according to a thirdembodiment in which electronic mail can be received. A component whichis the same as or similar to that shown in FIG. 1 is assigned the samereference numeral, and the detailed explanation thereof is omitted. Thisexample is different from the above mentioned embodiments in that itcomprises identification code assignment means 330 and direct electronicmail transmission means 334 as functions that the WWW server 300performs by the program stored in the WWW server 300 of the third maildistribution service center 30. Furthermore, the WWW server 300 isprovided with an identification code list database 340, and thesubscriber database 320 stores an identification code DASP and aspecified mail address associated with each subscriber.

The identification code DASP is a code indicating the attributeincluding the hobby, the liking, etc. of a subscriber and the attributeof a transmitter whose mail can be received by the subscriber in theelectronic mail among many and unspecified persons. The subscriber isassigned an identification code when he or she subscribes to the thirdmail distribution service center 30. To assign the identification code,a plurality of inquiry items and corresponding alternatives are preparedin a pull-down menu. In response to the inquiry items, the subscriberanswers on the WEB. Based on the answer, the identification codeassignment means 330 determines a corresponding identification code.FIG. 12 shows examples of the inquiry items and alternatives. Theinquiry items are the sex, address, birthday, hobby, liking, etc. of thesubscriber. Relating to a transmitter, the inquiry items are thepersonality, location, purpose, business type, employment, scale, etc.of the transmitter which can be accepted for the subscriber. It is notnecessary to answer all of the inquiry items. The subscriber can decidethat all electronic mail from all unspecified persons would be acceptedwithout answering an inquiry, or all electronic mail from allunspecified persons would be rejected. Finally, the subscriber specifiesan electronic mail address (specified mail address) to be received inthe electronic mail from the unspecified sources. The mail address canbe any of the second electronic mail addresses, or a quite differentelectronic mail address can be specified. When any of the secondelectronic mail addresses is specified, the wireless telephone 40 canreceive the mail by the transfer as explained above by referring to thefirst embodiment. The identification code assignment means 330 storesthe determined identification code and the specified mail addressassociated with the subscriber in the subscriber database 320.

FIG. 13 shows an example of a list of identification codes stored in theidentification code list database 340. In this example, it is a 4-digitidentification code two digits of which are used as the attribute of thesubscriber and the remaining two digits are used as the attribute of thetransmitter. It is obvious that the identification code can berepresented by a larger number of digits for more detailed attributeclassification. The data stored in an identification code list database340 is published on the WEB. Furthermore, as shown in FIG. 14, the datacan be processed and published. In the example shown in FIG. 14, asimple code, a part of the attribute of a subscriber, a part of theattribute of a transmitter, the number of registrants, an example ofuse, etc. are listed. A company wishing to transmit electronic mailviews a published identification code list shown in FIG. 13 to selectthe attribute of the company itself and the attribute of a subscriber toreceive the electronic mail of the company, specifies an identificationcode, body data, etc., transmits them to the third mail distributionservice center 30, and requests the third mail distribution servicecenter 30 to transmit the electronic mail. Otherwise, it views apublished and processed list shown in FIG. 14, selects the attribute ofthe company itself and the attribute of a subscriber to receive theelectronic mail of the company, specifies a simple code, body data, andthe number of persons to receive electronic mail, transmits them to thethird mail distribution service center 30, and requests the third maildistribution service center 30 to transmit the electronic mail. Onesimple code is a set of a plurality of identification codes. If thenumber of persons that the company wishes to transmit the electronicmail is smaller than the number of registrants, the company furtherselects more detailed attributes, and requests the third maildistribution service center 30 to transmit the electronic mail. Thedirect electronic mail transmission means 334 of the third maildistribution service center 30 extracts a subscriber having thecorresponding identification code from the subscriber database 320,extracts the specified mail address of the subscriber, generateselectronic mail to the mail address, and then transmits the mail. Forexample, the company can request the third mail distribution servicecenter 30 to transmit advertising electronic mail to 100 subscribers whohave the common hobby, and are probable purchasers of a new product. Ifthe specified mail address is a second electronic mail address, it istransferred to the wireless telephone 40 through the third maildistribution service center 30 and the first mail distribution servicecenter 10. If the specified mail address is quite different from thefirst to the third electronic mail addresses used in this system, thenthe mail is not transferred to the wireless telephone 40.

For a subscriber who receives the mail, the electronic mail is anacceptable electronic mail. Therefore, the mail is not junk mail. If thesubscriber specifically likes one piece of the electronic mail, then theelectronic mail address gyousha@gyousha.co.jp of the electronic mail canbe extracted from the body of the electronic mail ‘This mail has beentransmitted from gyousha@gyousha.co.jp to taro@nif.ne.jp’ as shown inFIG. 7, and it can be specified as an acceptable electronic mail addressof the first mail distribution service center 10. The transmitter whoasks the third mail distribution service center 30 to transmit theelectronic mail can transmit the electronic mail to subscribers havingthe common hobby and liking. Therefore, transmitting insignificantelectronic mail can be avoided, thereby efficiently transmittingelectronic mail.

(Urging Subscription to Third Mail Distribution Service)

To effectively utilize the functions described above by referring to thefirst to third embodiments, it is important to urge a larger number ofsubscribers to subscribe to the third mail distribution service center30. Described below will be a system for promoting the subscription.

FIG. 15 is a block diagram of the configuration according to a fourthembodiment of promoting the subscription. In FIG. 15, the differencefrom the third embodiment is that the third mail distribution servicecenter 30 further comprises a receiver rank database 350 for storingranked data of subscribers (that is, a receiver) who receives theelectronic mail, and a transmitter rank database 352 for storing thedata evaluating a company which requests the third mail distributionservice center 30 to transmit electronic mail or a person (that is,transmitters) who requests to be evaluated. It comprises a premier mailtransmission means 360 as the function that the WWW server 300 performsby the program stored in the WWW server 300 of the third maildistribution service center 30.

The receiver rank database 350 stores the number of the premier mailreception count indicating the number of received pieces of the premiermail obtained by the subscriber for each month, and the rank for eachsubscriber. The rank is divided into a plurality of levels such asplatinum, gold, silver, metal, etc. by the number of the premier mailreception count. The premier mail is mixed at random at a certainprobability when the direct electronic mail is transmitted. Therefore,if a larger number of pieces of direct electronic mail is received, theprobability that premier mail can be obtained is stronger on thereceiver side. That is, if the range of the reception-enabledtransmitters from among unspecified persons is larger, then a largeramount of electronic mail can be received from many and unspecifiedpersons, thereby increasing the opportunity of receiving premier mail.In addition to the system of including premier mail at random, there isa system of intentionally including premier mail. In the intentionalsystem, the intention principle is basically non-published to thereceiver side. In the non-published system, not only the third maildistribution service center 30 intentionally performs the process, butalso, for example it, transmits electronic mail at an intentionalinstruction on the transmitter side. With a certain intention, a timeperiod, an attribute of a specific receiver, etc. is selected, andpremier mail is transmitted. A certain intention can be an intention ofthe third mail distribution service center 30, or can be an intention ofa transmitter. That is, the transmitter can be assigned a right todecide premier mail. To allow a receiver to obtain a larger amount ofpremier mail, the identification code of the subscriber to which thetransmitter requests to transmit the electronic mail, can be published.Then it is possible to promote the receiver to select the identificationcode more to receive the premier mail.

Then, the transmitter rank database 352 stores the number of votesindicating the evaluation of the transmitter for each transmitter. Thevoting is performed by a receiver. A receiver at a higher rank can beassigned a larger number of voting rights. The transmitter evaluated bythe vote of a receiver can be a company requesting the third maildistribution service center 30 to transmit electronic mail as describedabove in the third embodiment. In addition, the rights to capture votescan be obtained by applying for the third mail distribution servicecenter 30. The vote can be in the positive and negative manners, and avote can be transmitted by electronic mail to the third maildistribution service center 30. When the transmitter sells or providesan excellent product or contents to the receiver side, the transmittercan obtain a good evaluation from the receivers, thereby collecting alarger number of votes. A transmitter having a right to capture a votecan publish his or her corporate concept, personal creed, etc. on theWEB, and the subscriber can view them on the WEB. Thus, the transmittercan be checked by a consumer.

An incentive plan can be set to a receiver for each rank. The contentsof the receiver rank database 350 are processed, and the order of thehigher ranks can be viewed on the WEB so that the order can be checkedat any time by any receiver (for example, as shown in FIG. 16).Furthermore, the rule of raising a rank may be published. A privilegemay be set to the higher rank holders.

Furthermore, the contents of the transmitter rank database 352 areprocessed, and the higher order in the voting state can be viewed inreal time on the WEB. Ranking may be set depending on order. The rankingorder may be set by type of industry, or by person or company. A higherrank transmitter may be assigned a bonus of a large banner on the WEBsite. A transmitter can improve a corporate impression and obtain theprominence of the company name by obtaining a higher rank.

Not only a company, but also a person who is unsatisfied with a serviceor a product of a company, obtains a right to capture a vote to assertthe option on the WEB. With a consent of voter, a higher rank can beachieved, and the assertion can be more prominent. Thus, an almostillegal corporate crime can be removed, and a conventionally tabooproblem can be asserted. The prominence is enhanced with a larger numberof supporters, thereby establishing a published opinion reporting systemrelating to politics.

Thus, both transmitter and receiver can enjoy the merit of using thethird mail distribution service center, and the system that pleases bothtransmitter and receiver by participation can be provided. Usinganimation for the display contents on the WEB and voting for popularity,a ranking result can be obtained much more correctly than a TV ratingcheck. A broadband can prove its worth, thereby realizing infinitenumber of channels. Only the third mail distribution service can be a TVprogram table.

In the above mentioned embodiments, the third mail distribution servicecenter 30 is separate from the first and second mail distributionservice center 10 and 20. However, the present invention is not limitedto this concept, but the third mail distribution service center 30 canbe combined with any of the first mail distribution service center 10and the second mail distribution service center 20. That is, when thefirst mail distribution service center 10 is combined with the thirdmail distribution service center 30, electronic mail forwarded from thesecond mail distribution service center 20 is transmitted to the thirdmail distribution service center 30 where replacement means replaces asource, and it is transmitted with forwarding or without forwarding(that is, without changing the destination of electronic mail) to thefirst mail distribution service center 10 where it is processed byreception enable means. Otherwise, when the second mail distributionservice center 20 is combined with the third mail distribution servicecenter 30, the electronic mail received by the second mail distributionservice center 20 is transmitted to the third mail distribution servicecenter 30 with forwarding or without forwarding (that is withoutchanging the destination of the electronic mail), the replacement meansreplaces the source, the mail is transmitted to the first maildistribution service center 10. Furthermore, electronic mail isforwarded from the third mail distribution service center 30 directly tomailbox 122 of the first mail distribution service center 10 in theseembodiments. However, it can be forwarded indirectly, that is, from thethird mail distribution service center 30 to a further mail distributionservice center, and from the further mail distribution service center tothe first mail distribution service center 10. Additionally, it can beforwarded from the second mail distribution service center 20indirectly, that is, from the second mail distribution service center 20to a further mail distribution service center, and from a further maildistribution service center to the third mail distribution servicecenter 30.

As described above, according to the present invention, when junk mailtransmitted from many and unspecified persons is sent to a firstelectronic mail address registered in the first mail distributionservice center, the sources of the junk mail are not acceptableelectronic mail addresses, and the reception enable means rejectsreceiving the junk mail, thereby avoiding transmission of the junk mailto subscribers. On the other hand, the electronic mail transmitted frommany and unspecified persons and not to be rejected by the receptionenable means is transmitted to a second electronic mail address. Theelectronic mail to the second electronic mail address received by thesecond mail distribution service center is forwarded to the third maildistribution service center (intermediate mail distribution servicecenter), and the replacement means replaces the source with theacceptable electronic mail address registered in the first maildistribution service center, and the electronic mail is forwarded to thefirst mail distribution service center. Since the source is set to anacceptable electronic mail address, the reception enable means in thefirst mail distribution service center enables reception, and asubscriber can receive the electronic mail. Thus, the subscribercertainly receives the electronic mail whose source electronic mailaddress is not registered as acceptable electronic mail address, butwhich should be received by the subscriber when the electronic mail istransmitted from the source electronic mail address, thereby removingonly junk mail.

1. A junk mail rejection system, comprising: a first mail distributionservice center having a database in which a first electronic mailaddress of a subscriber is registered, receiving electronic mailtransmitted to the first electronic mail address through acable/wireless network, and transmitting the electronic mail to aterminal of the subscriber; a second mail distribution service centerhaving a database in which a second electronic mail address of thesubscriber is registered, and receiving electronic mail to the secondelectronic mail address through a cable/wireless network; and a thirdmail distribution service center having a database in which a thirdelectronic mail address of the subscriber is registered, and receivingelectronic mail to the third electronic mail address through acable/wireless network, wherein said first mail distribution servicecenter registers in the database one or more source electronic mailaddresses as acceptable electronic mail addresses, associated with thefirst electronic mail address, from which electronic mail can betransmitted to a terminal of a subscriber among source electronic mailaddresses of electronic mail addressed to the first electronic mailaddress, and comprises: reception means for receiving electronic mail tothe first electronic mail address; reception enable means fordetermining whether or not a source electronic mail address ofelectronic mail received by said reception means is an acceptableelectronic mail address registered in the database; and distributionmeans for transmitting the electronic mail to a terminal of a subscriberonly the case when the reception enable means determines that it is anacceptable electronic mail address; said second mail distributionservice center registers an electronic mail address of a transferdestination of a subscriber in the database associated with a secondelectronic mail address, and comprises reception means for receivingelectronic mail to the second electronic mail address; and transfermeans for forwarding the electronic mail received by said receptionmeans to a third mail distribution service center directly through acable/wireless network, or through another center; and said third maildistribution service center registers an electronic mail address of atransfer destination of a subscriber in the database associated with athird electronic mail address, and comprises reception means forreceiving electronic mail to the third electronic mail address;replacement means for replacing a source electronic mail address of theelectronic mail received by said reception means with one of theacceptable electronic mail addresses; and transfer means for forwardingthe electronic mail whose source has been replaced by said replacementmeans to said first mail distribution service center directly through acable/wireless network, or through another center.
 2. The junk mailrejection system according to claim 1, wherein said second electronicmail address is registered as one of the acceptable electronic mailaddresses registered in the database of the first mail distributionservice center, and said replacement means of said third maildistribution service center replaces a source electronic mail addresswith the second electronic mail address.
 3. The junk mail rejectionsystem according to claim 2, wherein said replacement means replacesdestination data of the electronic mail received by said reception meanswith the source data, and replaces the source data with the destinationdata.
 4. The junk mail rejection system according to claim 2, whereinsaid replacement means adds the source data and/or destination databefore replacement to information of a body of electronic mail.
 5. Thejunk mail rejection system according to claim 1, wherein said third maildistribution service center further comprises mail reception amountrestriction means for determining whether or not electronic mailreceived in a predetermined time period has exceeded a predeterminedamount, and the electronic mail is rejected when the electronic mail hasexceeded the predetermined amount.
 6. The junk mail rejection system,according to claim 1, wherein said third mail distribution servicecenter has a database storing for each subscriber an identification codeindicating an attribute of a subscriber and an attribute of atransmitter whose electronic mail is permitted by the subscriber, anddirect electronic mail transmission means for transmitting electronicmail to a specified mail address of a subscriber selected by theidentification code.
 7. The junk mail rejection system according toclaim 6, wherein said direct electronic mail transmission meanstransmits electronic mail selected at random or intentionally as premiermail.
 8. The junk mail rejection system according to claim 7, whereinsaid third mail distribution service center has a receiver rank databasestoring the number of pieces of obtained premier mail for eachsubscriber, and allows contents of the receiver rank database to beviewed on WEB as is or after being processed.
 9. The junk mail rejectionsystem according to claim 8, wherein said third mail distributionservice center has a transmitter rank database storing the number ofvotes of subscribers who evaluate a transmitter for each transmitter ofelectronic mail transmitted by said direct electronic mail transmissionmeans, and allows contents of the transmitter rank database to be viewedon WEB as is or after being processed.
 10. An intermediate maildistribution service center, provided between a first mail distributionservice center having a database in which a first electronic mailaddress of a subscriber is registered, receiving electronic mailtransmitted to the first electronic mail address through acable/wireless network, and transmitting the electronic mail to aterminal of the subscriber only when a source of the electronic mail hasan acceptable electronic mail address permitted in advance fortransmission to a terminal of the subscriber; and a second maildistribution service center having a database in which a secondelectronic mail address of the subscriber is registered, and receivingelectronic mail to the second electronic mail address through acable/wireless network, comprising: reception means for receivingelectronic mail to a second electronic mail address received by saidsecond mail distribution service center; replacement means for replacinga source of the electronic mail received by said reception means withthe acceptable electronic mail address determined by said first maildistribution service center; and transfer means for allowing theelectronic mail replaced by said replacement means to be transmitted tothe first mail distribution service center.
 11. The intermediate maildistribution service center according to claim 10, wherein one of theacceptable electronic mail addresses predetermined in said first maildistribution service center is the second electronic mail address, andsaid replacement means replaces a source with the second electronic mailaddress.
 12. The intermediate mail distribution service center accordingto claim 11, wherein said replacement means replaces destination data ofthe electronic mail received by said reception means with the sourcedata, and replaces the source data with the destination data.
 13. Theintermediate mail distribution service center according to claim 11,wherein said replacement means adds the source data and/or destinationdata before replacement to information of a body of electronic mail. 14.The intermediate mail distribution service center according to claim 10,comprising mail reception amount restriction means for determiningwhether or not electronic mail received in a predetermined time periodhas exceeded a predetermined amount, and the electronic mail is rejectedwhen the electronic mail has exceeded the predetermined amount.
 15. Theintermediate mail distribution service center according to claim 10,further comprising direct electronic mail transmission means having adatabase storing for each subscriber an identification code indicatingan attribute of a subscriber and an attribute of a transmitter whoseelectronic mail is permitted by the subscriber, and direct electronicmail transmission means for transmitting electronic mail to a specifiedmail address of a subscriber selected by the identification code. 16.The intermediate mail distribution service center according to claim 15,wherein said direct electronic mail transmission means transmitselectronic mail selected at random or intentionally as premier mail. 17.The intermediate mail distribution service center according to claim 16,wherein said intermediate mail distribution service center has areceiver rank database storing the number of pieces of obtained premiermail for each subscriber, and allows contents of the receiver rankdatabase to be viewed on WEB as is or after being processed.
 18. Theintermediate mail distribution service center according to claim 17,wherein the intermediate mail distribution service center has atransmitter rank database storing the number of votes of subscribers whoevaluate a transmitter for each transmitter of electronic mailtransmitted by said direct electronic mail transmission means, andcontents of the transmitter rank database are viewed on WEB as are orafter being processed.